The present invention relates to an arm/rotor hub assembly and a method of assembling the same, and more particularly to such an assembly in which the arms pass through apertures in the rotor sidewall and are flared outwardly within the rotor to a diameter greater than that of the apertures.
Arm/rotor hub assemblies are utilized in a variety of different applications, one common application being the stationary or rotating garden sprinkler. In the sprinkler application, the interior of an upright, generally cylindrical hollow rotor is in fluid communication with a fluid supply (for example, by means of a flexible hose). Transversely-extending hollow arms pass through the rotor sidewall and are in fluid communication with the interior of the rotor, the outwardly extending ends of the arms being typically provided with nozzles communicating with the rotor interior through the hollow arms. The length of the sidewall of the arm portion extending outwardly from the rotor may also be provided with small apertures (whether also equipped with nozzles or not) to provide additional means of egress for the water.
Clearly a critical consideration in such an assembly is that the rotor/arm interface is fluid-tight so that fluid does not leak out of the rotor interior through the interface and accumulate on the ground immediately adjacent to the rotor. Furthermore, the assembly must be sufficiently strong to prevent such leakage of water through the interface even at elevated water pressure, such as 125 psig. Usually as part of the technique for preventing such leakage, and in any case in order to insure that the spray pattern of the sprinkler remains constant, the arms should be constrained from movement relative to the rotor. Finally, the method of assembling the arms to the rotor should be simple, inexpensive, and relatively fail-proof.
Accordingly, it is an object of the present invention to provide an arm/rotor hub assembly in which the arm/rotor interface is substantially fluid-tight.
Another object is to provide such an assembly which substantially precludes motion of the arms relative to the rotor.
A further object is to provide a simple, inexpensive and relatively fail-proof method of assembling such an arm/rotor hub assembly.